chapin



UNITED STATES PATENT OFFIC LUCIUS D. CHAPIN, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE CHAPIN PNEUMATIC IRON COMPANY, OF SAME PLACE.

IAPROCESSOF MAKING waoucHT-leow.

SPECIFICATION forming part of Letters Patent No. 2 91ATO, dated January 1,1854.

Application filed June 23, 1883. (No specimens.)

In all whom it may concern:

Be it known that I, LUCIUS D. CHAPIN, a

citizen of the United States, residing at Chilates to practice the same.

i In an application forLetters Patent filed by me inthe United States Patent Office on the 3d day of October, 1881, Ihave described and claimed a process of making wrought-iron y by which molten cast-iron is subjected, in a Bessemer converter having a fire'brick, ganister, or like silicious lining, to the action of an air-blast until the objectionable impurities, which the air-blast is adapted to re-- move, shall have been substantially eliminated,and thentransferring the metal to aseparate rotary furnace or balling chamber having preferably an oXide of-iron lining, and therein subjecting it to a reverberatory flame and to puddling action until it is reduced to a wrought condition to form a ball orloop. For

i the practice of such process the apparatus illustrated in my patent of January 3, l880,was

preferably employed. The metal was run from acupola or blast: furnace into a Bessemer or pneumatic convertenand therein subjected to the action of the air-blast for a short time say for ten minutes, more or less-either till the metal approached nature or approached a corrresponding degree or stage of purification; or the blow was shortened somewhat, if

desired, although in any case the metal was kept under the air-blast treatment until the objectionable impurities which it was desired to remove by the air-blast were substantially eliminated. The metalwas next tapped, run, or otherwise transferred into a puddling or balling chamber having an iron-oxide lining adapted to nourish the iron and aid in its conversion, and of such construction as to admit the use of a reverberatory flame and a mechanical puddling action. In such ballingvessel the metal was treated until brought to a wrought conditionto form a puddled ball or loop.

separated from the metal.

(Patent No. 283,074, August 14, 1883,) except that in this improvement, which is specially applicable to such gradesof cast-iron as are high in their content of phosphorus, I provide for the elimination of phosphorus from the crude metal containing such impurity in injurious quantity by the use of dolomite. The preferred manner of using the dolomite is as follows: The phosphoritic metal,'mellted in a cupola or blast furnace, is run therefrom into a Bessemer or pneumatic converter, and is there blown, in manner above described,until the impurities which the air-blast is adapted to remove shall have been substantially eliminated. The charge of metal is next run into atransferring ladle in the bottom of which has been placed a quantity of dolomitewhich unites with the phosphorus of the iron and forms a slag that may be readily removed. The metal remains in the ladle only for a time sufficient to allow the reactions to occur and the slag to rise to the surface, which will usually not require more than eight minutes, approximately, care being taken lest the metal become chilled by remaining in the ladle for too long a time. From the ladle the charge of metal is run into the puddling or balling vessel having an oxide-ofiron lining, in which has been placed a further quantity ofdolomite, and is there subjected to a puddling action, preferably by the rotation or oscillation of the vessel, until it is brought to the condition of wrought-iron, after which the ball or loop of metal will be withdrawmand may be run into muck-bars in the usual manner. The dolomite in the puddling or balling chamber will be found to act upon such phosphorus as ma remain in the iron after it leaves the ladle, and will form a slag which may be .readily In crude iron containing, say, from .3 to .5 of one per cent. of phosphorus the quantity of dolomite employed may be about four to five per cent. of the entire oharge that is to say, ninety-five to ninety-six per cent. crude iron and five to I Bessemer converter having a refractory linfour per cent. dolomite. It will be obvious, however,'that these proportions may be varied to suit the different characters of metal under treatment, and the quantity of dolomite will be increased or diminished according as the-metal contains a greater-or less per centage of phosphorus. The dolomite may be used either in a raw or calcined condition, but I prefer that the quantity employed in the ladle should be raw, while that used in the balling-chamber should be calcined. In some cases the entire charge of dolomite may be placed in either the ladle or the balling-chamher; but, as stated, the preferred manner of treatment is to place a portion in each, for by so doing the operation is not materially lengthened, a 1 more effective action of the dolomite is obtained, and all danger of chilling the metal is' avoided. Y '1' By the above-described improved process a very superior quality of wrought-iron can be quickly obtained from pig metal containing phosphorus in such quantity as would render it totally unfit for the production of wrought iron by the processes heretofore practiced.

I am well aware that the use of dolomite in eliminating phosphorus from crude iron is old; but,

Having thus described my inventiomwhat I claim'as new, and desire to secure by Letters Patent, is y l. The process of making wrought-iron from crude or'cast iron high in phosphorus, which consists in subjecting such molten iron, in a ing, to the action of an air-blast until the objectionable impurities Whichthe air-blast is adapted to remove shall have been substantially eliminated, and then transferring the metal to a separate furnace or balling chamber having, essentially, an oXide-of-iron lining, and therein subjecting it to reverberatory flame and to puddling action until brought to a wrought condition to form a ball or loop, dolomite being added to the metal during its treatment, substantially as described.

2. The-process of making wrought-iron from crude or cast iron. containing phosphorus in injurious quantity, which consists in subjecting molten cast-iron. in a Bessemer converter having a refractory lining, to the action of an air blast until the obj ectionable impurities which the air-blast is adapted to remove shall have been substantially elintiinated, then transferring the metal to a ladle wherein dolomite is'placed, and then transferring the metal to an iron-oxide lined balling or puddling chamber wherein dolomite is placed, and there subjecting it to a reverberatory flame and to a puddling action until it is reduced to a Wrought condition to form a ball or loop, substantially as described.

In testimony whereof I have hereunto set my hand.

LUcIUs n. oHArm.

in presence of Gno. P. FIsI-IER, J11,

L. C. CHAPIN. 

